Or was its performance so bad that there was no other way of knowing ...?

Not sure if you're pulling our legs but I'll bite just the same The chroma indicator as far as I can tell was nothing more than a gimmick, I have such a feature on my G25K502 ( see below).

The one on the G6 ( far more funky than the GEC red light) is an electro/mechanical jobby, in that behind the rectangular window is a little tube one half green, one half white. When the chroma is present the voltage makes the tube pivot to green when no chroma it pivots back. Another feature is the colour off button below why theses features? Like you I thought what on earth is the use! I've no idea but I suppose if you've shed out a small fortune for colour then why not have an indicator and button to impress the neighbours to show your colour prowess

Perhaps there's a more technical reason that escapes me that those far wiser can provide and answer to.

The off button might be useful in areas where the signal is poor on one channel and good on the others.It can then be used to get rid of all that spotty reception. Such a control would have been useful in the early days of channel 5 in some areas.

I would think that the "colour off" button would be useful to force the set into displaying black and white transmissions in the bluish white people were used to on true black and white sets when the broadcasters forgot to turn the burst off.

ISTR the first G6s had a relay on the tube base to tweak the greyscale when watching monochrome to make the picture slightly blue tinted to replicate a mono set? In my experience the colour beacon on the GECs usually stopped working after a few years. Most of the ex rental sets I had didn't have a working lamp. To be honest I don't know if the rental firm had disabled it in some way or if it was a fault. apart from checking the bulb I never bothered going any further as I couldn't see the point of the light at the time anyway. By this time the sets were being used on 625 only.I remember selling a 25" to a mate at schools parents for £80, the first colour set I sold. £80! Bloomin good money at the time!I would also love one for my collection now..

The G6 Colour Off push button is independent of the auto white relay on the CRT base. It gives a correct b&w picture, the auto white relay would still activate on a b&w transmission.

Many 2028 colour beacons didn't work or functioned dimly owing to the wrong value resistor from the bridge rectifier being fitted. Seems this didn't bother most people when the set was new. It's a useful fault finding feature as a b&w image owing to a CDA fault would still illuminate the beacon. It won't light up if the fault is in the decoder.

I once fitted a colour beacon to a single std GEC hybrid colour set!

Back to what this thread is about, I would like to see a GEC 2017 with VHF radio again and of course a Defiant 9A61U which started my TV fascination from an early age in the first place.

If it's fully-restored and in perfect working condition like the CVC2 I think you can expect to pay a fairly hefty sum.

If however it's a complete wreck which needs dozens of hours of skilled labour and thousands of pounds worth of test equipment to restore to working condition you will still probably have to pay a fairly hefty sum!